Pulp digester with interior circulation



April 21, 1931- I E. MORTERUD 1,802,266

PULP DIGESTER WITH INTERIOR CIRCULATION Filed .Oct. 10, 1929 I I I' I L:

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Patented Apr. 21, 1931" UNITED STATES PATENT orl-lcs EINAR IOBTERUD, OI TOBDEROD, NEAR MOSS, NORWAY PULP DIGISTER WITH INTERIOR CIRCULATION Application filed October 10, 1929. Serial No. 898,750.

The present invention relates to pulp digesters having an interiorcirculation system,

and the object of the invention is to provide a circulation system of this kind which will 6 be simple, cheap and eflective, and which will not in any way form an obstruction to the digested pulp when the same is tobe removed from the digester.

In accordance with the invention these oblo jects are attained by means of a circulation system comprising a substantially straight vided with a circulation system in accordance with the present invention.

Fig. 2 is a detail showing the circulation system as seen from the inside of the digester.

The circulation system comprises a pump 1, which may be of the reversible or ordinary type, and which is secured to the shell 2 of the digester in some convenient manner. The suction side of pump 1 communicates with an interior sieve 3, which is in the form of an approximately straight tubular member haying its lower end adjacent the apex of the conical bottom section 4 of the digester, and extendin along the inside of the said bottom in $1151 a manner as to form no obstruction to the digested pulp when the same is to be removed through the bottom opening 5 of the digester. V

The outlet side of the pump communicates with a tubular heating chamber 6, which is secured to the digester shell at a point between its ends by means of a tubular shank 7 Through this tubular shank passes a steam inlet pipe 8, which communicates inside the heating chamber 6 with a steam introduction pipe 9 located coaxially with the tubular heating chamber 6.

At its upper end the tubular heating chamber 6 communicates with an outlet sieve 10, which may be of approximately the same type as inlet sleve 3 conforming more or less accurately to the curvature of the inner top wall of the digester.

As it has been stated, pump 1 may be a reversible pump, in which .case sieve 10 will act as intake sieve and sieve 3 as outlet sieve.

Claim:

In a pulp digester a heating chamber comprising a tubular member located along the innerwall of the digester near the central part thereof, a tubular shank attached to the said tubular member between its ends for securing the same to the digester shell, a steam introduction tube passing. through said tubular shank to the interior of the said tubular heating chamber, acirculation pump communicating with one end of said heating chamber and an outlet'sieve communicating with the other end of said heating chamber.

In testimony whereof, I aflix my signature.

EINAR MORTERUD. 

